Re: Where is the performance bottleneck?
From: Nick Piggin <hidden>
Date: 2005-08-31 12:24:10
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Holger Kiehl wrote:
3236497 total 1.4547 2507913 default_idle 52248.1875 158752 shrink_zone 43.3275 121584 copy_user_generic_c 3199.5789 34271 __wake_up_bit 713.9792 31131 __make_request 23.1629 22096 scsi_request_fn 18.4133 21915 rotate_reclaimable_page 80.5699
^^^^^^^^^ I don't think this function should be here. This indicates that lots of writeout is happening due to pages falling off the end of the LRU. There was a bug recently causing memory estimates to be wrong on Opterons that could cause this I think. Can you send in 2 dumps of /proc/vmstat taken 10 seconds apart while you're writing at full speed (with 2.6.13 or the latest -git tree). A dump of /proc/zoneinfo and /proc/meminfo while the write is going on would be helpful too. Thanks, Nick -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com